1. Field of the Invention
The present invention relates generally to the field of canning and food preservation. More specifically the present invention relates to a vacuum jar apparatus including a bell jar and a vacuum pump lid which both closes and seals the jar and pumps air out of the sealed jar. The lid includes a lid lower portion in the form of a sealing disk having a disk lower face covered with a sealing gasket material for extending across and sealing the jar upper rim, and having a downwardly extending circumferential lip for receiving the jar upper rim to center the lid on the jar, and a pumping mechanism for evacuating air including a chamber within the lid structure having an internal volume which is enlargeable and reducible. A first air passing port is provided between the chamber and the jar, and a first check valve in the first air passing port oriented to permit air to pass from the jar into the chamber and to prevent air from passing from the chamber into the jar through the first air passing port. A second air passing port is provided between the chamber and the atmosphere outside the chamber and the jar, and a second check valve in the second air passing port oriented to pass air from the chamber into the atmosphere outside the chamber and the jar and to prevent air from passing from the atmosphere outside the chamber and the jar into the chamber. A mechanism for enlarging and a mechanism for reducing the volume of the chamber is provided, so that sequentially enlarging and reducing the volume of the chamber progressively expels air from the jar through the chamber and into the atmosphere outside the chamber and the jar, thereby progressively rarefying air remaining in the jar to ultimately approach a vacuum.
2. Description of the Prior Art
There have long been jars and cans for retaining foods and other perishable items such as paints which have a very short shelf life if exposed to air outside the jar or can. A problem with prior jars has been that there is no practical or efficient way for an ordinary consumer to sufficiently evacuate air within the jar to preserve the contents. A problem with prior cans is, once again, that the ordinary consumer has no practical way of evacuating air within the can to preserve its contents, and then when the can is sealed it cannot be opened and subsequently re-evacuated, so that all of the contents must be used at one time to avoid loss through spoilage or solidification.
It is thus an object of the present invention to provide a vessel which includes a lid with a manual air pump for pumping air out of the vessel to preserve the vessel contents.
It is another object of the present invention to provide such a vessel in which the manual air pump is operated by twisting the lid circumferential outer wall back and forth, for convenient manual operation.
It is still another object of the present invention to provide such a vessel which is conventional in general appearance and suitable for compact stacking and storing.
It is finally an object of the present invention to provide such a vessel which is durable and inexpensive to manufacture.